It is well known that there are two kinds of golf clubs which are called "wood" and "iron". Of the two, a wood is said to be more difficult for beginners to precisely hit a ball with since a wood is usually faster in head speed on a hit than that of an iron. One solution proposed is to make a bigger head to extend its appropriate hitting area for the purpose of facilitating a correct hit with a wood. It should be noted that a bigger head is consequently accompanied by a heavier weight which increase the difficulty of hitting with a wood.
As has been known by those skilled in the art, there are two methods of producing a head of a wood, one is called "injection molding" in which a resin with carbon powder is injected into a die to form a head and the other is called "compression molding" in which stacked carbon sheets are compressed to form a whole. With either of these two methods, after molding the head, a plate-like face to hit a ball is attached to the leading side of the head.
Some heads are provided with a cavity therein in an attempt to avoid an increase in their weight in consequence of an increase in their volume. However, those heads with a cavity have a problem of shortage of durability because relatively high distortions of the heads during hits due to the existence of the cavity deteriorates the connection of the face to the head over long use.